Stainless steel has been so far used for engine cylinder head gaskets requiring an LLC (long life coolant) resistance, but any good liquid-resistant adhesion durability cannot be obtained even by direct application of a vulcanizing adhesive to the stainless steel, followed by vulcanization bonding of rubber thereon, resulting in peeling the bonded rubber, when subjected to immersion tests.
The present applicant has so far proposed a fluororubber-metal laminate gasket material, which comprises a metallic steel sheet, a zirconium element-, phosphorus element-, and aluminum element-containing surface-treating agent layer, a silica-containing thermosetting phenol resin-based vulcanizing adhesive layer, and a fluororubber layer, as successively laid upon one another on the metallic steel layer, as a fluororubber-metal laminate gasket material free from peeling of the bonded layer even if used in an electrolyte at the same time with a different metal species in the actual gasket use circumstances, thereby proving to hold the adhesiveness for a sufficiently long time.                Patent Literature 1 JP-A-2006-218629        